There are approximately 600 naturally occurring carotenoids, but only six of these have so far been produced industrially. Insofar as applicants are aware, the only companies that manufacture synthetic “nature-identical” carotenoids at the present time are Roche (since 1954) and BASF (since 1960). Lycopene, a member of carotenoids, exhibits high radical scavenging ability and gives the health protection against a variety of serious disorders including cancer, heart disease, and degenerative eye diseases. Accordingly it has been widely used as an excellent additive in food, fodder and drugs. Indeed, chemists at Roche have developed an industrially feasible synthesis of lycopene characterized by Wittig condensation, but it requires the use of a very costly raw material triphenylphosphine. (See: K. Meyer, et al., Helv. Chim. Acta 1992, 75.1848.) Almost all early existing methods suffered from the use of triphenylphosphine.
A new synthesis method of lycopene (1) was reported in WO 0031086 by Babler et. al., in which diethyl 3,7,11-trimethyl-2,4,6,10-dodecatetraenylphosphonate (8) reacted with C10-dialdehyde (9) catalyzed by base to afford lycopene.

Thus lycopene can be prepared by the above four-step route starting with pseudoionone, in which 2,4,6,10-C15-tetraenylphosphonate (8) has been employed as the key intermediate and the triphenylphosphine discarded, and many improvement including a more simplified route has been observed compared with the known methods. But this new method still suffered from some limitations: the reagent C1P(OEt)2 is hard to prepare and sensitive to water and air; the costly NaBH4 and Pd/C is inevitably used as the hydrogenation reagent and catalyst; the selectivity of partial reduction is somewhat uncontrolled during the course of the conversion from allenic phosphonate compound (7) to allylic phosphonate (8) because of the competition between 1,2-allenic part and 4,5-double bond of phosphonate (7). So it is not suitable for industrial-scale production.
Recently, Shen et al has reported a new method for synthesis of lycopene (CN 201010189861.0), in which C14-acetal (2) was employed as the key intermediate:

But this method still have some disadvantages that it is very difficult to gain the raw material dialkyl 4-methyl-5,5-dialkoxy-1-pentene-1-phosphonate (10) because no effective synthesis method can be adopted; furthermore, C14-acetal (2) prepared by this method is composed of several cis and trans isomers, which can't be converted to its all-trans form.